Actuators are used in myriad devices and systems for the control of rotary valves. For example, many vehicles including, for example, aircraft, spacecraft, watercraft, and numerous other terrestrial and non-terrestrial vehicles, include one or more actuators to effect the movement of various rotary valve components, such as butterfly valves, ball valves, etc. One type of actuator that has been designed and implemented with rotary valves is a linear actuator.
In many instances a rotary valve and electromechanical actuator (EMA) are mounted to the vehicle and thereby increase the overall weight of the vehicle. Typically, these rotary valve and EMA systems include pressurized fluid that enters and expandable chamber to drive a piston, which is mechanically connected to a valve shaft of the rotary valve. This driving action by the piston causes the valve shaft to open or close the rotary valve.
These types of traditional rotary actuators are known in the art to control the operation of an associated valve by converting the linear stroke of the piston to a rotational movement of a driving member that engages the valve. The actuator is typically mounted in a cantilevered position relative to the valve body and includes a multi-sectioned lever type actuating arm that moves in response to the linear movement of the piston. The cantilevered actuator in these types of systems creates a high overhang moment. In addition, this type of offset piston drive valve includes a relatively long piston stroke to actuate the valve, thereby increasing the weight of the overall valve.
It should thus be appreciated from the above that it would be desirable to provide a compact and lightweight electromechanical actuator and valve assembly that eliminates the long piston stroke and high overhang moment. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.